Is it possible to “see” sound! Absolutely! This module explores sound waves and focuses on amplitude – what we commonly refer to as “loudness.”
Attitude for Amplitude!
Attitude for Amplitude!
Sound waves rock and roll – literally! In this module we’ll catch a wave or two and see how they measure up using our databot sound sensor.
Overview
Grades:
Time:
Subject:
5-8
50 minutes (PDQ’s + Experiment)
50 Minutes (Challenge & Collaboration)
Physics
Is it possible to “see” sound! Absolutely! This module explores sound waves and focuses on amplitude – what we commonly refer to as “loudness.”
Let’s check it out. Listen up!
Background
Sound is a huge part of our life as we listen to music, communicate, and experience various levels of noise around the clock. Sound is actually a physical “thing” that you can measure, see, and even control. databot™ has a built-in sound sensor, a microphone, that enables you to capture sound data, visualize it, and better understand it.
Sound is transmitted through a medium such as air, in the form of waves. Imagine tossing a pebble into a pond and watching the waves spread out from the point of impact. This is how sound behaves. It spreads out from its point of origin and has some very specific characteristics that enable us to identify each exact sound. The ability to record sound and play it back is based on capturing and replicating those unique characteristics exactly! The drawing below, next to the water ripple, is an illustration of two characteristics of a sound wave: 1) Amplitude; and 2) Frequency.
- Amplitude is the height of the wave – a big ripple has a high amplitude. With sound, amplitude, also called “intensity,” corresponds to “loudness.”
- Frequency corresponds to “pitch” or tone and is how fast the sound wave is vibrating. When you sing that high note, you are hitting a higher (faster) frequency!
The activities in this module explore sound waves further with databot™ and focus on amplitude, or intensity.
Sound intensity (amplitude) is measured in units called decibels. The decibel scale is logarithmic, which means doubling the decibel units does not double the output, it can increase as much as 100 times! Normal conversation is about 60 dB, a soft whisper around 30 dB, and a lawn mower about 85 dB. When you look at the sound intensity output from databot™, it is reading in decibels.
The following chart gives you a general idea of the decibel levels of common sounds.
The working range for your databot sound sensor is 0-70 dB, and it is highly sensitive to lower noise levels and background noise as you will see when using it.
Objectives
Understand:
- That sound is transmitted in waves.
- A microphone (sound sensor) vibrates from sound waves and converts this vibration to electrical energy.
- Sound intensity is measured in decibels – a unit of measurement.
- Two important sound wave properties are frequency, and amplitude.
- A sound wave needs a medium through which it can travel.
- Sound travels at different speeds through different mediums.
What You'll Need
- databot™
- Android smart device or Chromebook with Bluetooth Low Energy (BLE) to connect to databot™.
- databot™ Arduino Link App + Google Science Journal App installed on your Android or Chromebook device.
- A tone generator to control sounds for experiments. Many free apps exist for this purpose. See the resources section for suggestions.
- Common materials to test sound transmission through different mediums. Wood, plastic, books, glass, metal, etc. Find a selection of materials with similar thickness for best comparisons.
- Measuring tape and something to mark distances as students measure sound intensity changes related to distance.
Important Terms
Microphone: A microphone, sometimes referred to as a mike or mic, converts sound into an electrical signal.
Sound Wave: Sound is a vibration that travels in waves through a medium, such as air, water, wood, metal, etc.
Sound Pressure: We are constantly surrounded by pressure from the atmosphere – it’s invisible, but it’s there. Sound waves are measured using the same units and will record as a deviation from the standard air pressure around us. Sound and air pressure are both measured in Pascals (Pa).
Vibration: Vibration is an oscillating (back and forth) movement, like a vibrating reed in a clarinet. This vibration results in a sound wave that then travels through a medium, like the air.
Pitch: Pitch is the highness or lowness of sound. Pitch is how humans hear different frequencies.
Frequency: Frequency is determined by the number of vibrations per second. The highest key on a piano, for instance, vibrates 4,000 times per second
Amplitude: The amplitude or peak amplitude of a wave is a measure of how big its oscillation is.
decibel (db): Sound intensity is measured in units called decibels. The decibel scale is logarithmic, which means doubling the decibel units does not double the output, it can increase as much as 100 times! Normal conversation is about 60 dB, a soft whisper around 30 dB, and a lawn mower about 85 dB. When you look at the sound intensity output from databot, it is reading in decibels.
Wavelength: Sound waves, like any wave, repeat in a predictable fashion. You see repetition when you toss a pebble in the pond. The distance between the repeating shapes is called wavelength. If you were to measure from the crest of one puddle ripple to the next, that is its wavelength. Measure fast!
Medium: In physics, a transmission medium is the substance that transmits the energy from a wave. The standard transmission medium for sound that we know well is air, but water, wood, clay, metal, etc. are all potential mediums through which sound can travel.
Prep
Read the background information, study the terms, and explore the additional resource links.
Ready to get started? Let's go!
Next stop – PDQ1 – that means Pretty Darn Quick. Go dog, go!
This way to PDQ1
Educator Info
Educator Info
- Read the background information, study the terms, and explore the additional resource links.
- Do the PDQs and Experiment and review the accompanying educator information.
- Review the Coding and Collaboration extensions if of interest.
Understand:
- That sound is transmitted in waves.
- A microphone (sound sensor) vibrates from sound waves and converts this vibration to electrical energy.
- Sound intensity is measured in decibels – a unit of measurement.
- Wave property of amplitude.
- A sound wave needs a medium through which it can travel.
- Sound travels at different speeds through different mediums.
- NGSS PS4.A Wave Properties
- Sound moves faster in the air than in other mediums such as through a wall or underwater.
- Sound intensity, or loudness, is often confused with sound pitch, or tone.
- Sound can be heard in space (those dramatic science fiction explosions are silent – there is no medium to transmit the sound)
- Sound is not dangerous.
- If a tree falls in the forest and there is no one around to hear it, does it make a sound?
- If two asteroids collide in space, how close do you need to be to hear it?
- Will sound travel faster underwater or through the air if you need to cry “shark” to your friends?
- What does “sound pressure” mean?
- What is the difference between frequency and intensity?
Tone Generators for Conducting Experiments
- Tested and recommended: Phyphox. A free app for Android and IOS that reads the sensors on your smart device for experiments. It includes a built-in tone generator. Check your app store – free and simple to use! https://www.phyphox.org
- Tested and recommended: Physics Toolbox and Sensor Suite. Similar to Phyphox, works on IOS and Android platforms and reads your smart device sensors. Has a built in Tone generator. Check your app store and enjoy! https://www.vieyrasoftware.net/
- If you are using your computer, either MacOS or Windows, search for free tone generators. There are many.
Acoustics Society of America
CDC: What Noises Cause Hearing Loss?
https://www.cdc.gov/nceh/hearing_loss/what_noises_cause_hearing_loss.html
NASA – The Sounds of Space
https://www.nasa.gov/vision/universe/features/halloween_sounds.html
Misconceptions about sound
http://amasci.com/miscon/opphys.html
Explain that Stuff – Sound
Wikimedia Commons
https://commons.wikimedia.org/wiki/File:Pulse_wave_33.33_percent_Fourier_series_50_harmonics.png
Ripple cover image by Benjamin Balazs from Pixabay.
Water Drop by Diagram courtesy David Becker on Unsplash
Loudness of Common Sounds
Lumen Learning [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]
https://upload.wikimedia.org/wikipedia/commons/5/5e/Loudness_of_common_sounds.jpg
Can You See the Music? by Robert O. Grover & Team databot™ is licensed under a Creative Commons Attribution 4.0 International License. Permissions beyond the scope of this license may be available at databot.us.com/contact.
